The present invention relates to the general field of fiber preforms obtained by three-dimensional weaving and comprising two distinct portions that present outlines of different shapes and that are connected together by a zone of non-interlinking.
Certain fiber preforms obtained by three-dimensional weaving include zones of non-interlinking that make it possible, using a single flat-woven preform, to make parts out of composite material that are complex in shape. For example, they might be fan blade platforms for an aviation turbine engine that can be obtained from n-shaped fiber preforms having a base and two legs forming stiffeners, the base constituting one portion and the two legs constituting another portion that is distinct from the base portion, the portions being connected together by a zone of non-interlinking.
One of the problems encountered with making such preforms is that the profiles as cut out from the two non-interlinked portions of the preforms (constituting their final outlines) are not necessarily the same. In such a situation, it is not possible to envisage using waterjet cutting, so it is necessary to cut out the profiles of the two portions of the preform manually, one after the other.
However, it is difficult to control manual cutting out of a fiber preform, which can lead to cutting inaccuracies, and to problems of reproducibility and of loss of fibers.